The invention relates to four-joint cabinet hinges for door-opening angles of more than 105.degree.. Such hinges have, as the carcass-related part, a supporting arm which can be adjustably fastened on a mounting plate previously installed on the supporting wall of a cabinet carcass. The door-related part is a cup which can be sunk and fastened into a recess in the back of the door leaf to be mounted on the carcass. These parts are coupled together by means of two hinge links each pivotally mounted at one end on the supporting arm and at the other in the cup on pivot pins held in the supporting arm and cup, respectively. The hinge link that is on the outside when such hinges are in the open position has pivot eyes formed on opposite longitudinal sides. In each of these eyes a short pivot pin projecting from the associated cup wall is engaged such that a free passage is left between the confronting ends of the pivot pins to accommodate the inner hinge link.
Such four-joint hinges of increased opening angle have in recent times been widely used in the manufacture of furniture, since they are only slightly more expensive than the formerly commonly used four-joint hinges which opened mostly to 90.degree. or in any case no more than 105.degree., and which are of much simpler design and thus cheaper to manufacture than the so-called wide-angle crosslink hinges using a crossed link mechanism. On account of the cinematic conditions, the cup end of the outer hinge link cannot be mounted on a full-length pivot pin as in the older four-link hinges, because the inner hinge link passes through the cup-end pivot axis of the outer hinge link during the closing movement. It is for this reason that short pivot pins projecting from the wall of the cup and engaging the lateral pivot eyes on the cup end of the outer hinge link are used, which are fastened in the material of the cup; for this purpose the pivot pins are made larger than their bores in the cup, and they are press-fitted therein. To enable such press-fit mounting to be strong, the depth of the bores receiving one end of the short pivot pins must not be too shallow, i.e., they can be made only in cups having sufficient wall thickness in the area of the pivot-pin bores. This has been accomplished by making the cups by die-casting from a zinc alloy (Zamak), concentrating extra metal at the appropriate places. Making hinge parts of die-cast zinc alloy, however, involves a relatively high cost in the material and in the energy required for the casting process, so that an effort was made to produce such hinge parts as economically as possible by punch-pressing them from sheet steel. Consequently, hinge-mounting cups are increasingly being made more economically in this manner. However, the thickness of a cup made from sheet steel depends on the original thickness of the stock, and it is evident that the wall thickness of such a sheet metal cup will not suffice to hold pivot pins at only one end in bores in the wall. For this reason, four-link wide-angle hinges of the kind in question are still being manufactured only by the die-casting method.
Consequently, the invention is addressed to the problem of creating four-joint cabinet hinges for door-opening angles of more than 105.degree., which will be provided with a cup made by punch-pressing from sheet metal.